Hou Meiling, Zhang Xin, Fu Chao, Cen Wanglai, Chen Jiaxing
College of Engineering, Hebei Normal University, Shijiazhuang, 050024, P. R. China.
Phys Chem Chem Phys. 2020 Feb 28;22(8):4692-4698. doi: 10.1039/c9cp05920b. Epub 2020 Feb 14.
The catalytic removal of methane (CH) in exhaust emissions of natural gas-fueled vehicles is still a major challenge for automotive manufacturers because of the high CH-H bond energy and high concentrations of water (HO). Density functional theory (DFT) calculations were employed to investigate the adsorption of CH and HO, as well as the activation of CH, on the surface of a Pd-Pt bimetal supported by γ-AlO. These are significant factors for catalytic combustion. Pt addition weakened the bonding of the intermediates and increased the availability of electrons on the surface. Besides this, the γ-AlO surface and Pt were both beneficial for preventing the aggregation of clusters. CH and HO adsorption, as well as the detailed mechanism of CH activation on the Pd-Pt/γ-AlO surfaces were simulated. The results showed that a Pt/Pd ratio of three resulted in the best catalytic activity among the different ratios examined in the presence of HO.
由于甲烷（CH₄）中C-H键能高以及天然气燃料汽车尾气排放中高浓度的水（H₂O），催化去除天然气燃料汽车尾气中的甲烷对汽车制造商来说仍是一项重大挑战。采用密度泛函理论（DFT）计算研究了CH₄和H₂O在γ-Al₂O₃负载的Pd-Pt双金属表面的吸附以及CH₄的活化。这些是催化燃烧的重要因素。添加Pt减弱了中间体的键合，并增加了表面电子的可用性。除此之外，γ-Al₂O₃表面和Pt都有利于防止团簇聚集。模拟了CH₄和H₂O的吸附以及CH₄在Pd-Pt/γ-Al₂O₃表面活化的详细机理。结果表明，在有H₂O存在的情况下，在所研究的不同比例中，Pt/Pd比为3时催化活性最佳。
